You're a real cool player. You bravely fight your way through all the enemy defenses, battle through into the basements, nab the intel, and come back up topside just in time for everyone you killed along the way to have respawned and camping the exits, rewarding your valiant heroic efforts with a swift and thankless death. Then the Engineers rebuild their sentries, TurtleMania ensues, and the intel goes back into the depths again. Wash, rinse, repeat, and hello stalemate and thoroughly disappointing experience.